Not only the fittest survive

March 28, 2011

Researchers at the Universities of Exeter and Bath in the UK have called into question Darwin’s principle that only the fittest survive, says Professor Robert Beardmore and colleagues.

Together with a group from San Diego State University, the researchers tested Darwin’s principle by constructing very simple environments in the lab to see what happens after hundreds of generations of bacterial evolution, about 3,000 years in human terms.

They showed that while the fit use food well, they aren’t as resilient to mutations as unfit consumers that are maintained by their resilience to mutation. If there’s a low mutation rate, survival of the fittest rules; but if not, lots of diversity can be maintained.

The mutation rate of the experimental bacteria was high enough that both fit and unfit could co-exist.